Lubricating system for turbine-shaft bearings.



PATENTED MAR. 12, 1907.

- A. H. KRUESI.

LUBRIUATING SYSTEM FOR TURBINE SHAFT BEARINGS.

APPLIOATION FILED SEPT. 30, 1905.

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No. 846,796. PATENTED MAR. 12, 1907.

i A. H. KRUESI. 1 LUBRIGATING SYSTEM FOR TURBINE SHAFT BEARINGS.

APPLICATION FILE D SEPT. 30. 1905.

3 SHEETS-SHEET 3.

JUL/$418 6 Krues UnITEn STATES PATENT OFFICE.

AUGUST HKKR'UESI, 6F SCHENECTADY, NEW YORK, ASSIGNOR To GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LUBRI CATING SYSTEM FOR TURBINE-SHAFT BEARINGS.

Specification of Letters Patent.

Patented March 12, 1907.

Application filed September 30,1906. Serial No. 280,784.

To all whmn it may concern:

Be it known that I, AUGUST H. KRUEsI, a

citizen of the United States, residing at 1 Schenectady, county of Schenectady, State 5 of New York, have invented certain new and useful Improvements in Lubricating Systems for Turbine-Shaft Bearings, of which the following is a specification.

My invention relates to shaft-bearings, and relates more particularly to lubricating systems for combined step and guide bearings of the type used in connection with upright turbine-shafts; and it has for one of its objects to provide a lubricating system whereby a forced or positive flow of lubricating fluid can be maintained directly to each bearing either from a common source supplying them in parallel or from a separate source for each bearing, as desired. When the bearings are supplied from a single source, the maximum pressure of the supply is determined by the requirements of the step-bearing. This pressure must .be sufficient to hydraulically support the shaft and its attached parts and is at times as high as one thousand pounds per square inch. This pressure is obviously much greater than that re uired for the guide-bearing. Therefore a resistance or pressure-reducing device is employed in circuit between the source of supplyand the guide-bearing, so that the quantity supplied to the latter relative to the quantity supplied to the step-bearing will be properly proportioned.

It has been proposed hitherto to cause fluid exhausted from the step-bearing to pass through and lubricate the guide-bearing. In case of accidental failure of pressure in such an arrangement the bearing-blocks of the step-bearing come into contact, and more or less material is ground away. When pressure is restored, these articles mix'with the exhaust and flow with it to the guide-bearing,

lodging in the same and causing the bearing parts tobe more or less serlously out. By,

vacuum-chamber. Arranged in this manner there is a tendency for air to leak through the bearing-casing, due to-the effects of a' vacuum in the condenser system. To prevent this and maintain the vacuum unimpaired, the supply of fluid to the guide-bearing besides lubricating the same has the additional function of serving as a packing between the shaft and the bearing, the pressure being of such a value and the direction of flow of the fluid through the bearing being such as ,to practically prevent leakage of air. In case the pressure on the step-bearing should fall while the shaft is rotating and a vacuum is maintained in the exhaust-base of the turbine a suction is produced through the bearing which tends to draw the fluid back from the drainage-conduit through the bearingcasing and the guide-bearing, carrying with it the gritty material and particles ground 7 off of the bearing-blocks of the step-bearing,

resulting in the particles cutting the guidebearing surfaces. In order to overcome this, I employ a check-valve inthe drainage-conduit, which closes against any suction produced by the vacuum in the exhaust-base,

but permits the free discharge of the lubricant exhausted from the'bearings.

For an understanding of the details of construction and the particular features of novelty reference is to be had to the following description and to the claims appended hereto.

In the accompanying drawing, which illustrates certain embodiments of which the invention is capable, Figure 1 is a central vertical section of the bearing structure for a turbine-shaft, and Figs. 2 and 3 are similar views showing modifications.

Referring to the drawing, 1 represents a portion of the bottom of the chambered base of a turbine into which extends the vertical bucket-whcel-carrying shaft 2, a portion of one of the wheels being shown at 3. The turbine-base is chambered to receive the exhaust from the bucket-wheels, which is condensed therein by means of a condenser arranged therein or is discharged into a condenser separate therefrom. In the bottom of the turbine-base is a central opening in which is fitted the bearing-casing 4. The shaft 2 extends into the casing from the top and is suported u on bearing-blocks 5 and 6 in the ower en and is held against lateral displacement by the guide-bearing 7 in the upper endof the casing. The adjacent surfaces of the two-step bearmg-blocks are chambered out to form a pr(.-,ssure-chamber 8, to which fluid I is supplied from a suitable source by the conduit '9, that communicates with the chamber S through the central bore in the lower bearing-block (5. The pressure of the fluid sup- )llHl to the chamber 8 is such as to hydraulically support the weight of the shaft and its attached parts and maintain a film between the bearing-blocks. The fluid forming said film passes,continuously from the chamber 8 to the space surrounding the blocks which constitute a drainage-chan1ber. In order to' adjust the clearances between the moving buckets and the adjacent part, the shaft is adapted to be vertically-adjusted byineans of ing, which has an outside taper to correspond bottom bearinglock is keyed to the shaft 2 to rotate a screw 10, which screws into a threaded opening extending centrally through the head or late 11 of the casing. The upper therewith, while the lower block is prevented from turning by means of studs 12 secured in the head 11. In order to guide the movement of the lower block during the vertical adjustment of the shaft, it is provided with a piston-like extension 13, that moves in a cyindrical depression 14 in the head 11.

The interior surface of the upper part of the bearing-casing is finished by a tapering cut to receive the shell 15 ofthe guide-bearwith that of the casing. The lower end of the shell is provided with a circumferential flange 16, by means of which the screw-bolts 17 secure the shell in the casing. Carefully fitted in the shell and secured thereto is a removable wearing-sleeve 18. In order to prevent wear on the shaft proper, a sleeve 19 is secured thereto, the outer surface of which engages the inner surface of the sleeve or lining of the bearing. This sleeve is also removable. A slight clearance is provided between the lining and the sleevein which a body of lubricating fluid is adapted to flow..

This fluid is supplied to the clearance from an annular groove 2-0, located centrally between theends of the lining or sleeve 18, the fluid flowing by reason of its pressure to the opposite ends of the bearin The exhaust fluid from the lower end of t e guide-bearing discharges intothe chamber surrounding the step-bearing, while that from the upper end In the present system of tends to cool the guide-bearing. In the branch conduit 22 a baffling or pressure-reducing device 26 is arranged, its object being to reduce the pressure of the fluid from that suitable for the step-bearing to that suitable for the guide-bearing. The pressure of the lubricant for the guide-bearing should be suflicient to maintain a positive flow be tween the bearing-surfaces thereof and the shaft and also to prevent leakage of air into the turbinebase. from the two bearings discharges through a conduit comprising a passage 27 in the head 11 and a conduit 28 leading back tothe source of supply. In order to prevent a reverse flow of fluid through the drainage-con- The fluid exhausting y is of fluid is maintained around the shaft, which duit under the suction produced by the' vacuum in the turbine-base when the pressure of the lubricatin .system fails, a check valve 29 is arranged t erein. By preventing the return of fluid to the bearing the particles of metal ground out from the bearingblocks are prevented from being carried-up into the guide-bearing, where injury to the bearing-surfaces would result.

ICC

In Figs 2 and 3 the structural features of the bearings are the same as those shown in Fig. 1, and similar parts are designated by similar reference characters.

Referrihg to Fig. 2, the supply of fluid to the guide-bearing is conveyed through a conduit 30, which extends through the bottom of the turbine-base and connects at its discharge end with the annular groove 20 of the bearin -linin Where the conduit extends throng the base, a packing 31 is arranged to prevent leakage. A baflier or pressurereducing device 26 is also employed in the supply-conduit.

As to the construction shown in 3, the branch supply-conduit is dis ensed with and a simple bore 32 is provide in the turbineof the passage and its length determining the final pressure of the fluid that passes to the guide-bearing. The bafiiing device in Figs.

1 and 2 may be, and preferably is, a member similar to the plug 33, but inclosed in a suit able casing provided therefor.

In accordance with the provisions of the patent statutes I have described the principle of the operation of my invention, together with the apparatus which I now consider to represent the bestembodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried outb other means. What I claim as new, and esire to secure by Letters Patent of the United States, is 1. The combination of a shaft, a A stepbearing, a guide-bearing, a casing inclosing the bearings, and a source of lubricant under pressure which is common to and supplies both bearings in parallel.

2. The combination of a shaft, a step-bearing therefor, a guide-bearing, a casing inclosing both of the bearings, and a lubricating system which supplies lubricant in parallel to the bearings at different pressures.

3. The combination of a shaft, relatively rotatable bearing-blocks therefor, a-source of fluid under a pressure-sufiicient to maintain a lubricating-film between the blocks, a guidebearing, a casing containing both bearings, and a pressure-reducing means which receives fluid from said source and supplies it to ,the guide-bearing.

4. The combination of a shaft, a step-bearing therefor comprising relatively rotatable blocks, a guide-bearing for the shaft, a casing in which both bearings are located, aconduit for supplying fluid under pressure to the step-bearing to maintain a lubricating-film between the blocks, a second conduit leading from the first to the guide-bearing, and a means in the second conduit for reducing the pressure of the fluid supplied to the guidebearing.

5. The combination of a chambered base,

a shaft extending into said base, two relatively rotatable bearing-blocks forming a step-bearing for the shaft and having a chamber between them, a guide-bearing forthe shaft, a conduit for supplying fluid under pressure to saidchamber to maintain a supporting-film between the blocks, a second conduit leading from the first at a point with out the base to a point within the base to supply fluid to the guide-bearing, and a means in the second conduit for reducing the pressure of the fluid before it is delivered to the guide-bearing.

6. The combination of a chambered base, a shaft extending into the base, a step and guide bearing for the shaft, a casing for the bearings containing a chamber which receives all of the exhaust-lubricant from the step-bearing and a part of the exhaust from the guide-bearing, a second chamber that receives the remainder of the exhaust from the guide-bearing, conduits that supply lubricant to the step and guide bearings, and a conduit that discharges the lubricant'from the first-mentioned chamber.

7. The combination of a chambered base, a shaft extending into the base, a guide-bearingfor the shaft, a casing for the guide-bearing having a drainage-chamber, means for supplying fluid under pressure to the guide' bearing at a point mtermediate its ends whereby the fluid. flows between the shaft and bearing and exhausts from the ends of the latter respectively into said chamber and chambered base, and means for conveying away fluid from said drainage-chamber.

8. The combination of a chamberwhich is adapted to contain vapor under a pressure different from that of the atmosphere, a shaft extending into the chamber, a guidebearing therefor between which and the shaft fluid .under pressure tends to pass, means for maintaining a flow of fluid between the shaft and bearing for lubricatingthe same and also preventing the passage of fluid under pressure between the atmosphere and the chamber.

9. The combination of a chamber which is adapted to contain vapor under a pressure different from that of the atmosphere, a

shaft extending into the chamber, a stepbearing for the shaft, a guide-bearing for the shaft between which and the shaft fluid under pressure tends to pass, means for maintaining a flow of fluid through-the step-bearing and between the shaft and the guidebearing for lubricating the same, and also preventing the passage of fluid due to the difference 1n pressure between the atmosphere and the chamber.

10. The combination of a shaft, a stepbearing, a guide-bearing, means for supplying a lubricant to the step-bearing at a pressure sufficient to support the shaft, a means for supplying lubricant to the guide-bearing, a casingfor both bearings containing a chamber which is located between the bearings and receives the drainage from both, and a drainage-conduit leading from the chamber.

11. The combination of an exhaust-chamber adapted to contain vapor at a pressure below atmosphere, a shaft extending into the said chamber, a step and guide bearing for the shaft, means for supplying lubricant to the bearings, a drainage-conduit for conveying away the lubricant-exhaust from the bearings, and a check-valve in said conduit for preventing the return of exhaust to the bearings under the influence of the low pressure in the chamber.

12. The combination of an exhaust-chamber adapted tocontain vapor at a pressure below atmosphere, a shaft extending into the chamber, step and guide bearings for the 4 Meme shaft which are ermhged in the chamber, In witness whereof I havehe'reunto set my means 1for supplylng' lubrgcanfi i gdependently hand this 25th'day of September, 1905. to th'e earings acaisin 9ft e earin s c0n tainiiig a chanibefint \7vhich lubrica nt ex- AUGUST S 5 hausts, a drainage-conduit connected with Witnesses:

the chamber, and a check-valve in said con- A W. L. BLENKISON,

duit, I S. M. BARBOR. 

